AO Smith GPSH 50 100 Anode replacement

Hi all,
I have an AO Smith GPSH 50 100 water heater that was purchased in 2004. For the last few weeks, I have noticed on the top, the gasket under the blower assembly has been wet and there is water in the catch pan under the heater. I removed the blower and all the connections to the heater were wet (cold, hot, and anode). I found a lose connection in the cold water connection and tightened it up and dried everything out with my shop vac blower. This morning, the gasket is wet again but the hot and cold connections were dry, so I suspect the anode connection is leaking so I was going to replace the anode. The questions I have are:
1) Could it be anything else other than the anode? (I don't think the blower would suck water up from the bottom...)
2) Any suggestions on replacing the anode? Besides calling someone, the only other option I have is replacing the unit which I can do myself. (I've read the heater is a dog. Mine won't stay lit and locks out the ignitor every now and then, I've sanded the temp probe and that helps a little)

Thanks for the reply. I was hoping that was the issue, but the fact that when I took the power vent off the vent tube itself was dry and the vent drainage tube was dry led me to think it was something else. I have read about a couple of others who have had this issue and it may be a cracked tank...